The present disclosure concerns a method for detecting an analyte, a carbon capture process comprising the method, a nitrosamine detector for detecting presence of a nitrosamine analyte in an amine solvent, and a carbon capture plant comprising the detector.
Contribution of the greenhouse gas carbon dioxide (CO2) to global warming is well-documented. One promising step to limit the release of CO2 to the environment e.g. from power plants, is through post-combustion carbon capture. In one example, CO2 from flue gases is dissolved by an amine solvent in a carbon capture process or plant. The amine solvent comprises an aqueous solution of an amine such as monoethanolamine (“MEA”), to form carbonate and carbamate ions. Unfortunately, a by-product of this approach can be the formation in the amine solvent of nitrosamines such as N-nitrosodiethanolamine (“NDELA”), e.g. from a reaction of amines with nitrogen oxide compounds (NOx) that may be present in the flue gas. Such nitrosamines are considered to be carcinogenic even at very low concentrations, e.g. a few parts per million (ppm). Therefore, for carbon capture processes using amine solvents to become more acceptable, there is a need to deal with the possible nitrosamine contamination.
For example, WO2013/023919 describes a method and device for purification of a nitrosamine-contaminated product from a process plant wherein the contaminated product is treated with UV radiation from a UV light source such that nitrosamines are destroyed. There remains a desire for an improved method and/or detector for detecting the presence and/or concentration of nitrosamines in the amine solvent, e.g. to determine whether a treatment is efficient or even necessary at all. More in general there is a need for a detection method having improved specificity and sensitivity to a selected analyte which method can be implemented inline for continuous monitoring of a process flow such as carbon capture.